Fix message thread reply footnote view not shown if parent message not in cache

[nuno-vieira]

🔗 Issue Link

Fixes https://linear.app/stream/issue/IOS-559/thread-reply-footnote-view-not-shown-in-reply-show-in-channel

🎯 Goal

Fixes messages thread reply footnote view not shown when the parent message is not in cache.

🛠 Implementation

Problem

The issue is that in order to render the MessageRepliesView, we require a parentMessage. We get the parentMessage from the dataStore, but if the parent message is from an old page, it will return nil since it won't be in the local DB.

We can't change the parentMessage parameter to an optional since that would be a breaking change, and changing the Factory protocol could even lead to a silent breaking change for our customers.

Solution

1st try: Breaking Change

This one is tricky to solve without breaking changes. First, I tried to force a breaking change by making the function in the Factory @unavailable. But this is not possible. It is only supported by @objc protocols. Since we have default implementations of the factory, creating a real breaking change would be silent for customers, so this is not an option.

2nd try: Hack-ish Workaround

The first solution I did without breaking change was to provide the message reply as the parent message as well. Then, check if they had the same ID, and treat it as if parentMessage was nil. You can see the implementation here.

The problem with this approach is that it is very hacky and unexpected. I customer would need to know about this hack if they wanted to customize the view.

3rd try: Final Solution

The solution I found the best was to create a Lazy view of the existing MessageRepliesView. Whenever the parent message does not exist in the local cache, we fetch it and then display the view. From here on, it will be in the local cache until we logout, so it won't be always fetching.

This approach requires the least changes on our side and no changes on the customer side. The con, is whenever this case happens, it means additional requests will be made just to display a footnote view. Ideally, this request would only be executed only when opening the Thread View, but unfortunatly, until we have v5, there's no alternative.

🧪 Testing

1. Open a Channel
2. Load old pages
3. Create a Thread Reply and check "Send also in channel"
4. Logout
5. Open the same Channel
6. The "Thread Reply" footnote should be shown in reply created in 3.

🎨 Changes

Below is the fix demo. The thread reply view takes a bit of time to load since it is lazy-loaded and requires performing a request to show it.

Fix
Simulator.Screen.Recording.-.iPhone.16.Pro.-.2024-12-05.at.18.52.50.mp4

☑️ Checklist

• I have signed the Stream CLA (required)
• Changelog is updated with client-facing changes
• New code is covered by unit tests
• Affected documentation updated (docusaurus, tutorial, CMS (task created)

[Stream-SDK-Bot]

SDK Size

title	develop	branch	diff	status
StreamChatSwiftUI	7.47 MB	7.53 MB	+66 KB	🟢

[martinmitrevski]

Great idea and solution, it's the best we can do atm ✅ Left one suggestion, let me know what you think.

[martinmitrevski]

shouldn't we do this only onAppear? init can be called many times.

[nuno-vieira]

Xcode 15 was not happy with the current implementation, so I moved to onAppear, but this requires changing from Group, to use a VStack

[github-actions]

	2 Errors
🚫	Please use more than one word. f81cf5d
🚫	Please remove period from end of commit subject line. f81cf5d

Generated by 🚫 Danger

[sonarqubecloud]

Quality Gate failed

Failed conditions
41.1% Coverage on New Code (required ≥ 70%)

See analysis details on SonarQube Cloud